Research & Methods Support (R&MS) Core Consistent with the overall mission and theme of the Center for Advancing Longitudinal Drug Abuse Research (CALDAR), the Research & Methods Support (R&MS) Core will provide support to CALDARaffiliated and other researchers for developing high-priority research questions and applying longitudinal research methods regarding drug use, treatment and recovery, HIV, and other service system interactions. The R&MS Core has the following specific aims: (1) To promote theoretical and conceptual development of CALDAR longitudinal research and associated research questions, generation of hypotheses, and synthesis of findings from longitudinal research on drug use and recovery; (2) To identify and provide support for conducting longitudinal research, specifically regarding fieldwork methods, subject retention, measurement, regulatory issues, and acquisition and use of administrative databases; and (3) To develop training materials regarding longitudinal research methods and research findings and assist in their dissemination, in collaboration with other CALDAR Cores. The R&MS Core will focus on developing research questions and applying methods that support, sustain, and improve the quality of longitudinal research on drug abuse. Core activities are designed to provide support, training, and consultation regarding methodological issues and challenges that are unique to longitudinal research, but are commonly encountered among researchers who endeavor to undertake this type of research. The activities of the R&MS Core will be accomplished through its workgroups on Theory, Measures, Regulatory Affairs and Administrative Database Acquisition; workgroups in the substantive areas of research (Drug Use and Recovery/Treatment, Mental Health, HIV, and Criminal Justice); and interactions with the Community Advisory Board. The R&MS Core activities will strengthen the ongoing research of CALDAR-affiliated investigators as well as the proposed and ongoing research of new and already-established investigators. The activities of the R&MS Core will be undertaken in collaboration with the other Center Cores with the goal of fostering theoretical development and application, innovation, thematic integration, multidisciplinary involvement, enhanced productivity, and synergy across research projects.